Added creation and desctruction of QtApp so that the FileDialog will work.

Extracted two methods from reshape_to_Ndims:
  get_sort_order returns the order of rows in a dataset or array from fastest changing to slowest
  get_dimensionality returns the number of unique elements in the rows of a dataset or array

see commits

This reverts commit f6b76db8.

Decomposition and other stuff

Removed the iPCA functionality

Needs testing and verification. Needs the allowable decomposition methods

Particularly useful for clustering / analysis. Note: these classes have NOT been tested

Conflicts:
	pycroscopy/io/io_hdf5.py
	pycroscopy/io/translators/be_utils.py

DOC: make some of the docstrings conform with NumPy style